The present invention relates to a weatherseal for releasably contacting a panel, and more particularly, to a weatherseal for releasably contacting a glass panel in an automobile, wherein the weatherseal includes a contact layer with a reduced coefficient of friction for allowing the glass panel to be smoothly moved into and out of contact with the weatherseal, while reducing passage of water or air between a seated glass panel and the weatherseal. Specifically, the present weatherseal includes a thermoset, thermoplastic or combined substrate having a contact layer for contacting a panel, wherein the contact layer includes a multitude of surface treated thermoplastic particles in a thermoset material.
Many vehicles employ windows formed of glass panels, wherein the window is moveable relative to a portion of the vehicle. A common construction includes the use of a glass panel in a door, wherein the door and the glass panel move relative to the remainder of the vehicle, and the glass panel moves relative to the door. In this construction, the glass panel is frequently moved between an open position and closed position with respect to the door and/or a portion of the vehicle frame. Increased business transactions such as restaurant, banking and pharmacy services are now regularly offered in a drive-through format. These transactions require the repeated release and engagement of the glass panel and vehicle. The repeated opening and closing of the glass panel places significant stress on the seal between the glass panel and the vehicle.
Traditionally, a weatherseal is employed at the interface between the glass panel and the vehicle door and/or the vehicle. The interface between the weatherseal and the glass panel must be sufficient to substantially preclude the penetration of water and air along the periphery of the glass panel, while still permitting ready engagement and disengagement of the glass panel without requiring significant force.
Conventional sealing structures include a soft synthetic resin or synthetic rubber. However, such weatherseals do not provide for the ready opening and closing of the glass panel relative to the seal. Further this structure often presents difficulty in securing of the door relative to the vehicle. Further, a large force is loaded on the window glass during opening or closing.
Therefore, the need exists for a weatherseal that has reduced force requirements for moving a glass panel into and out of engagement with the weatherseal. The need also exists for a weatherseal having enhanced wear capabilities. A need also exists for a method of forming a low friction weatherseal.
The present invention provides a weatherseal for repeatedly releasably contacting a panel, wherein the weatherseal has a reduced coefficient of friction between the weatherseal and the panel, while providing enhanced sealing characteristics. The weatherseal of the present invention also provides enhanced durability in terms of engagement/disengagement cycles.
Generally, the present weatherseal includes a substrate having a contact layer on a portion of the substrate, wherein the contact layer includes thermoplastic particles, at least partially embedded in a thermoset material. In one configuration, the thermoplastic particles are chemically bonded to the thermoset material. In a preferred configuration, the thermoplastic particles are ultra high molecular weight xe2x80x9cUHMWxe2x80x9d polyethylene and the thermoset material is a cross linked urethane. In a further configuration, the UHMW polyethylene particles are surface treated with reactive gasses prior to mixing with the urethane. It is also contemplated that the contact layer may be formed on only a portion of the weatherseal and that the contact layer may be formed as a layer.
The present invention contemplates the manufacture of a weatherseal by treating thermoplastic particles such as UHMW polyethylene or with reactive gasses, prior to combination with a thermoset material. In a preferred construction, the thermoset material is a cross linked urethane. The thermoplastic particles, such as treated UHMW polyethylene particles are then mixed with the thermoset material such as urethane and a quantity of silicone for lubricity. A substrate formed of materials such as EPDM or TPE is extruded and the thermoplastic particle-thermoset material mixture is applied to the extruded substrate. The thermoset material of the contact layer is then cured, wherein the discrete characteristic of individual thermoplastic particles is maintained.